在 PHP 中使用反射 class 也无法访问私有属性

Question

How to access private property values outside the class? I also tried using reflection in PHP.

<?php
namespace TDD;
class Receipt {

    public $user_id = 1;
    private $pending_amount = 45;   

    
    public function total(array $items = []){   
    $items[] = $this->pending_amount;
       return array_sum($items);
    }

    public function tax($amount,$tax){
        return $amount * $tax;
    }
    
    public function pending()
    {
        return $this->pending_amount = 45;
    }
    
    public function addTaxPending($tax){
        return $this->pending_amount * $tax;
    }
}


$class = new \ReflectionClass('TDD\Receipt');
$myProtectedProperty = $class->getProperty('pending_amount');
$myProtectedProperty->setAccessible(true);
$myInstance = new Receipt();
$myProtectedProperty->setValue($myInstance, 99);

echo $myInstance->pending_amount;


?>

Error: ` $ php src/Receipt.php PHP Fatal error: Uncaught Error: Cannot access private property TDD\Receipt::$pending_amount in C:\xampp\htdocs\all_scripts\PHPUnit_By_siddhu\src\Receipt.php:48 Stack trace: #0 {main} thrown in C:\xampp\htdocs\all_scripts\PHPUnit_By_siddhu\src\Receipt.php on line 48

Fatal error: Uncaught Error: Cannot access private property TDD\Receipt::$pending_amount in C:\xampp\htdocs\all_scripts\PHPUnit_By_siddhu\src\Receipt.php:48 Stack trace: #0 {main} thrown in C:\xampp\htdocs\all_scripts\PHPUnit_By_siddhu\src\Receipt.php on line 48 ` error screenshot

How can I solve it? Looking for your valuable solutions.

Answer 1

From the PHP manual for ReflectionProperty::setAccessible :

Enables access to a protected or private property via the ReflectionProperty::getValue() and ReflectionProperty::setValue() methods.

Calling setAccessible has no effect on access to the property via normal PHP syntax, only via that ReflectionProperty object.

So this line is still accessing a private property:

echo $myInstance->pending_amount;

You need to instead access it via your reflection object:

echo $myProtectedProperty->getValue($myInstance);